Andy Jennings said:many thanks Workingguy. Much appreciated.
I should have said that I am working from %MHR not watts. I am not even thinking about power meters at the level I am at currently. I have only got back in to cycling recently after 15 years of nothing due to illness.
What you state here makes perfect sense, although my logic was correct intensity, shorter duration.(I hadn't considerd an incorrect max intensity)
I would assume, in that case, that my estimated MHR, using the known to be inaccurate 220-age, is incorrect for me as well. I would not be at all surprised about this after so long as a couch potato.
Until I can justify the expense of a PM I will just have to go by %MHR and perceived effort to get the desired "Jeez I'm stuffed" result at the end of the effort. o_O
Good point about taking a break as well. I have been riding for 2-3 hours a day at a level that makes me moderatly tired at the end, split in to two rides. I may just need to back off and try again at the intervals. My main priority atm is health and calorie burn and that is why I have been riding so much.
Again thanks for the advice and guidance.
Looking at the chart in the pdf, I've never used heart rate as a training intensity guide. I can't imagine holding 100% max heart rate for 20 minutes. I'd pass out before reaching 106% MHR let alone hold it for 5 minutes. And keep in mind for a any interval, your heart rate takes about a minute to ramp up to the desired intensity,
If you have the means to do it, getting a power meter would be the best investment you can make. Above getting bike bling, titanium frame, deep rim carbon wheels, etc.
The cheapest option would be to let software like trainerroad.com estimate your power. All you need is a garmin (or wahoo) speed sensor, ANT stick (looks like a wireless mouse usb plug), and a supported trainer. Total cost = $300. It may give you low or high estimate, but then base your training intensity on that estimate. Make sure your setup is consistent, ie, not changing from one workout to the next. I'm using this because although I have a power meter, it is the old wired one, it's not connected via ANT+. So I don't care if trainer road gives me too low an estimate, my threshold workout targets will be 95% of that estimate. Just have to remember to watch the computer screen instead of my own power meter. Trainer road is $12/month or $99/year much less than the cost of a gym.